Silviculture Treatments for Ecosystem Management in the Sayward (STEMS) is a large-scale, multi-disciplinary experiment that compares forest productivity,
economics, and public perception of seven silvicultural regimes replicated at three sites in the Sayward Forest.
The STEMS experiment uses silvicultural systems and treatments to create diversity in forest structure that results in a variety of canopy layers (vertical structure) and spatial patchiness (horizontal structure) to enhance biodiversity and wildlife. The STEMS experiment examines seven different treatment
- Extended Rotation (non-treatment control)
- Extended Rotation with Commercial Thinning
- Uniform Dispersed Retention
- Aggregate Retention
- Group Selection
- Modified Patch Cuts
- Clearcut with Reserves
These silvicultural regimes create a range of gap sizes and frequencies that emulate natural variation in forest structure.
STEMS is a replication of the "Silvicultural Options for Harvesting Douglas-fir Young-Growth Production Forests" in the Capitol Forest near Olympia, Washington, developed jointly by the managers of the Washington State Department of Natural Resources and the scientists of the Pacific Northwest Research Station. The decision to replicate the treatments in the Sayward Forest was based on the similarity of knowledge gaps in the Sayward Forest and the Capitol Forest and because replication in Washington and British Columbia results in greater statistical power and ability to extrapolate over a wide geographic area.
This technical report describes the establishment of the first replication of STEMS in 2001 in the Snowden Demonstration Forest. Ongoing studies include:
- Tree growth and stand development, including understory vegetation
- Regeneration and light availability
- Windthrow, mortality, and coarse woody debris recruitment
- Harvesting production and impacts of residual tree damage and soil disturbance (in partnership with the Forest Engineering and Research Institute of Canada [FERIC])
- Visual quality and public response
The results of this experiment will be used to improve forest management and policies because results can be directly interpreted operationally due to the large-scale, replicated experimental design. The information will be especially relevant for forests with multiple use objectives.
Download Technical Report 017 PDF file (1735 KB)
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Updated May 11, 2007